This paper gives a brief introduction to basic principle and working mode of atomic force microscope （AFM）. Sample preparation methods and factors that affect the AFM imaging of polysaccharide are described in detai...This paper gives a brief introduction to basic principle and working mode of atomic force microscope （AFM）. Sample preparation methods and factors that affect the AFM imaging of polysaccharide are described in detail. Advance in using AFM for morphological observation and quantitative study on polysaccharide molecules are reviewed. Research on single molecule force spectroscopy of polysaccharide and determination and adjustment of conformational change of sugar residue are introduced. Perspective on further application of AFM in polysaccharide investigation is presented.展开更多
Objective： To study the effects of Astragalus polysaccharide （APS）, the primary effective component of the Chinese herb medicine Astragalus membranaceus （frequently used for its anti-hepatic fibrosis effects）, on...Objective： To study the effects of Astragalus polysaccharide （APS）, the primary effective component of the Chinese herb medicine Astragalus membranaceus （frequently used for its anti-hepatic fibrosis effects）, on nanoscale mechanical properties of liver sinusoidal endothelial cells （SECs）. Methods： Using endothelial cell medium as the control, 5 experimental groups were established utilizing different concentrations of APS, i.e. 12.5, 25, 50, 100, and 200μg/mL. By using atomic force microscopy along with a microcantilever modified with a silicon dioxide microsphere as powerful tools, the value of Young＇s modulus in each group was calculated. SAS 9.1 software was applied to analyze the values of Young＇s modulus at the pressed depth of 300 nm. Environmental scanning electron microscopy was performed to observe the surface microtopography of the SECs. Results： The value of Young＇s modulus in each APS experimental group was significantly greater than that of the control group： as APS concentration increased, the value of Young＇s modulus presented as an increasing trend. The difference between the low-concentration （12.5 and 25 μg/mL） and high-concentration （200μg/mL） groups was statistically significant （P〈0.05）, but no significant differences were observed between moderate-concentration （50 and 100μg/mL） groups versus low- or high-concentration groups （P〉0.05）. Surface topography demonstrated that APS was capable of increasing the total area of fenestrae. Conclusions： The values of Young＇s modulus increased along with increasing concentrations of APS, suggesting that the stiffness of SECs increases gradually as a function of APS concentration. The observed changes in SEC mechanical properties may provide a new avenue for mechanistic rasearch of anti-hepatic fibrosis treatments in Chinese medicine.展开更多
基金suppoted by the National High-Tech Research and Development Program of China(2002AA2Z4181)
文摘This paper gives a brief introduction to basic principle and working mode of atomic force microscope （AFM）. Sample preparation methods and factors that affect the AFM imaging of polysaccharide are described in detail. Advance in using AFM for morphological observation and quantitative study on polysaccharide molecules are reviewed. Research on single molecule force spectroscopy of polysaccharide and determination and adjustment of conformational change of sugar residue are introduced. Perspective on further application of AFM in polysaccharide investigation is presented.
基金Supported by WANG Bao-en Fibrosis Research Fund of China Foundation for Hepatitis Prevention and Control(No.20120147)Beijing Natural Science Foundation(No.7172187)Young Elite Scientists Sponsorship Program by China Association for Science and Technology(No.2016QNRC001)
文摘Objective： To study the effects of Astragalus polysaccharide （APS）, the primary effective component of the Chinese herb medicine Astragalus membranaceus （frequently used for its anti-hepatic fibrosis effects）, on nanoscale mechanical properties of liver sinusoidal endothelial cells （SECs）. Methods： Using endothelial cell medium as the control, 5 experimental groups were established utilizing different concentrations of APS, i.e. 12.5, 25, 50, 100, and 200μg/mL. By using atomic force microscopy along with a microcantilever modified with a silicon dioxide microsphere as powerful tools, the value of Young＇s modulus in each group was calculated. SAS 9.1 software was applied to analyze the values of Young＇s modulus at the pressed depth of 300 nm. Environmental scanning electron microscopy was performed to observe the surface microtopography of the SECs. Results： The value of Young＇s modulus in each APS experimental group was significantly greater than that of the control group： as APS concentration increased, the value of Young＇s modulus presented as an increasing trend. The difference between the low-concentration （12.5 and 25 μg/mL） and high-concentration （200μg/mL） groups was statistically significant （P〈0.05）, but no significant differences were observed between moderate-concentration （50 and 100μg/mL） groups versus low- or high-concentration groups （P〉0.05）. Surface topography demonstrated that APS was capable of increasing the total area of fenestrae. Conclusions： The values of Young＇s modulus increased along with increasing concentrations of APS, suggesting that the stiffness of SECs increases gradually as a function of APS concentration. The observed changes in SEC mechanical properties may provide a new avenue for mechanistic rasearch of anti-hepatic fibrosis treatments in Chinese medicine.
